1. Field of the Invention
This invention relates to a speed governor for a camera and particularly to a speed governor arranged to stabilize the operating speed of a member which operates at a high speed.
2. Description of the Prior Art
The conventionally known speed governors for cameras include slow governors which are arranged to give a predetermined length of time for a self-timer or a slow speed shutter time. Generally, these conventional speed governing devices are arranged to obtain a predetermined length of time by intermittently lowering the speed by means of an anchor. However, they produce a disagreeable sound as they operate. Besides, where they are used for a high speed operating member, the oscillation cycle of the anchor is too short for smoothening intermittent speed variations and exceeds the mechanical strength of the bearing provided for the anchor. Therefore, these conventional speed governors have been not suitable for high speed operating members.
The conventional known devices also include speed governors of the type adapted for a high speed operating member with gears used as the speed governor and arranged to follow a drive source. However, the effect attainable by the use of these cannot be expected to be more than the speed governing effect resulting from the rotational friction of the gears. Even if the predetermined length of time could be obtained from the use thereof, the speed would come to gradually increase during operation. Where the operating member is to be stopped at a desired position, the positional accuracy for bringing the operating member to a stop at the desired position is greatly affected by the variation in the speed of the operating member. For improvement in the stopping positional accuracy, therefore, the operating speed of the high speed operating member must be stabilized. In order to stabilize the operating speed of the high speed operating member, the mere use of the gears as speed governor has been inadequate and requires some further improvement.